1. Field
The present disclosure relates to a flat panel display device having an improved encapsulation structure for preventing permeation of moisture from the outside and a method of manufacturing the flat panel display device.
2. Description of the Related Technology
Flat panel display devices such as organic light emitting display devices may have thin and flexible structures, and much research has been conducted into the further development thereof.
An organic light emitting display device generally includes a display that may deteriorate due to permeation of moisture, and thus, requires an encapsulation structure for sealing the display to prevent permeation of moisture from an external environment. In most typical encapsulation structures, a thin film encapsulation structure in which a display is covered by a multi-layer including an organic layer and an inorganic layer that are alternately stacked are used. That is, the organic layer and the inorganic layer are alternately stacked on the display of a substrate, thereby sealing the display.
In such structures, the organic layer applies flexibility to the flat panel display device, and the inorganic layer prevents permeation of oxygen or moisture from the outside. Accordingly, in order to prevent permeation of oxygen or moisture from the outside, the organic layer is disposed inside the flat panel display device to be adjacent to the display, and the inorganic layer is disposed outside the flat panel display device.
However, when stacking the organic and inorganic layers, an edge tail, which is an edge portion of the organic layer protruding more to the outside than an edge portion of the inorganic layer, may be generated. Generally, when the organic layer and the inorganic layer are formed, a mask may be put on a substrate so as to correspond to the corresponding layer in order to form a pattern in the layer. The organic layer permeates a gap between the mask and the substrate, thereby forming the edge tail. Oxygen or moisture permeates the display through the edge tail, thereby resulting in deterioration in performances of the flat panel display device.
Removal of the gap between the mask and the substrate, which the organic layer permeates, has been proposed, by scraping out a lower portion from among ends of the mask contacting a boundary portion of the organic layer, that is, a portion contacting the substrate in an eaves shape.
However, in this case, since the mask does not distinctly regulate the boundary portion of the organic layer, there is still a possibility that an edge tail is formed because an edge portion may flow out of the organic layer.
Accordingly, in order to form an encapsulation structure that can be protected against permeation of moisture and oxygen, there is a need to develop a method for suppressing formation of the edge tail of the organic layer.